The disclosure relates to hydraulic unit of a vehicle brake system having a first pump element, which is assigned to a first brake circuit, and a second pump element, which is assigned to a second brake circuit. The disclosure further relates to the use of such a hydraulic unit in a vehicle brake system.
Hydraulic units are used in vehicle brake systems in order to be able to provide a regulated brake pressure in associated brake circuits. For regulating the brake pressure the hydraulic unit comprises, among other things, at least one pump element, the pump piston of which is displaceable in a pump cylinder. In the area where brake fluid flows into the pump cylinder, the pump piston is furthermore guided in a pump housing, in which an eccentric drive for the pump piston is also situated. The eccentric drive is achieved by means of a drive shaft driven by a pump motor.
Conventionally, multiple pump elements, which form a so-called multi-piston system, are arranged in the single hydraulic unit. As a rule these pump elements are arranged in bores of the hydraulic unit. The hydraulic unit is connected by means of associated brake fluid lines to a brake master cylinder, thereby forming a relatively rigid connection between the hydraulic unit and the brake master cylinder. Connected in this way, pressure pulses generated during pumping are transmitted to an associated brake pedal. Furthermore, the pulses are amplified by a splash wall that acts as a resonator and are transmitted to an associated vehicle interior. Noises and vibrations produced by this process are perceived as unwelcome phenomena.